Humpback Whales Learn Hunting Technique from Peers

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Evidence is mounting that several animals can learn behaviors
from their peers, and pass down these traditions from generation
to generation — an ability once thought to be uniquely human.

The latest study to document social learning in animals,
published today (April 25) in the journal Science, has found that
humpback whales learned a new feeding technique from other
humpbacks, a trait that stuck around and spread throughout the
population.

In 1980, a whale in the Gulf of Maine (off the coast of New
England) was first seen slapping its tail on the surface of the
ocean before feeding on a type of fish called sand lance. This
behavior soon spread and was passed down over several
generations. It's now a commonplace behavior in humpbacks
throughout the region, said Jenny Allen, a study co-author and
researcher at the University of St. Andrews in Scotland.

27 years of data

It is difficult, of course, to prove that a certain
behavior is learned socially, especially when it comes to
marine animals. But the researchers behind the study developed a
powerful computer model that allowed them to compare the
likelihood that this behavior arose via social interaction versus
individual learning.

Drawing upon a database of 27 years of observations of whale
foraging, the model returned a result that, at a bare minimum,
the humpbacks were 1 million times more likely to have learned
the feeding technique from peers than to have each learned it
individually.

"It was so big my supervisor made me run it again because he
thought I might have messed it up somehow," Allen told
LiveScience. "It was so startling to have that strong a result."

The whales perform this behavior, slapping their mammoth tales on
the surface one to four times, just before diving and
bombarding their prey with bubbles, which helps to organize
them into schools upon which the whales can more easily feed,
Allen said. The purpose of the technique, called lobtail feeding,
is unclear, but it's possible it helps organize the fish into
tighter formations before mealtime, she added.

Learning from peers

Whales learn the technique from other whales that they tend to
spend a lot of time with, the study found. Importantly, the
humpback whales didn't appear to learn the technique from their
mothers, said Jooke Robbins, a senior scientist at the
Provincetown Center for Coastal Studies in Provincetown, Mass.,
who wasn't involved in the study. That makes it easier to
conclude that the behavior is socially learned, as opposed to
genetically preprogrammed.

Humpbacks have somewhat loose social structures compared to other
whales; youngsters separate from their mothers after two years
and don't usually interact with them much after that, Allen said.
"They have associations that are kind of weak and flexible but
even in that situation you can have information that's
transmitted in a social context," Robbins said.

These whales, in other words, have multiple traditions. And they
likely have other socially learned behaviors and cultural quirks.
"The reason we were able to identify this is because it’s a
50-foot whale waving its tail at you. But there are probably many
other subtle behaviors that aren't as obvious and easy to
record," that are also culturally transmitted, Allen said.

Scientists have also found abundant evidence for social learning
and cultural transmission in a variety of primates. Another study
published today in Science found that wild vervet
monkeys can copy their neighbors' feeding habits, learning to
eat what "local" monkeys in new areas are eating.